Yup. Another good thing will be for the various big Cinerama-type 70mm houses to do the same thing. Show all of the extended versions back to back with only intermissions between them as a day long event. People would pay big bucks. Make it a first class affair with catered meals, T-shirts and paraphenalia. I'd do it. They could pack the house and charge a couple hundred a seat.
It might even become a recurring event, like Wagner's Ring series. This story is essentially that: Wagner for a new generation.
Having not seen it yet, I've been having trouble remembering the main melodic lines in the score. I keep trying to think of them but I always end up with "The Entrance of the Gods into Valhalla" from Die Gotterdamerung instead.
I agree with you on the "event" nature of showing all three movies together. Baltimore (about 45 minutes from where I live) has a theater called the Senator where it would be a great event. DC's Uptown could do it too, but it's a lot harder to get there for me (there aren't any good ways to get into DC from the north).